Silicone polyoxamide copolymers with amine-based end groups

Abstract

Silicone polyoxamide and silicone polyoxamide-hydrazide copolymers comprise at least two repeating units of formula (I). In this formula, each R1 is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo; each Y is independently an alkylene, aralkylene, or a combination thereof; each G is independently a bond or a divalent residue equal to a diamine of formula R3HN—G—HR3 minus the two —NHR3 groups; each R3 is independently hydrogen or alkyl or R3 taken together with G and with the nitrogen to which they are both attached form a heterocyclic group; each n is independently an integer of 0 to 300; each p is independently an integer of 1 to 25, and the average of p is 1.3 or greater; and each q is independently an integer of 1 to 2, and the average of q is no greater than 1.05.

1 . A method of making a copolymeric material comprising at least two repeat units of formula I′: 
       
         
           
           
               
               
           
         
         wherein:
 each R 1  is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo; 
 each Y is independently an alkylene, aralkylene, or a combination thereof; 
 each G is independently a bond or a divalent residue equal to a diamine of formula R 3 HN—G—NHR 3  minus the two —NHR 3  groups; 
 each R 3  is independently hydrogen or alkyl or R 3  taken together with G and with the nitrogen to which they are both attached form a heterocyclic group; 
 each n is independently an integer of 0 to 300; 
 each p is independently an integer of 1 to 25; and 
 each q is independently an integer of 1 to 2, and the average of q is no greater than 1.05 
 
         the method comprising:
 (a) adding an oxalate ester of formula II to a solvent 
 
       
       
         
           
           
               
               
           
         
         wherein:
 each R 2  is independently an alkyl, haloalkyl, aryl, or aryl substituted with an alkyl, alkoxy, halo, alkyoxycarbonyl, or 
 
       
       
         
           
           
               
               
           
         
       
       bound through the N, wherein each R 4  is independently hydrogen, alkyl, or aryl or R 4  taken together form a ring;
 (b) reacting the oxalate ester with a polydiorganosiloxane diamine of formula III until essentially no polydiorganosiloxane diamine or oxalate ester remains 
 
       
         
           
           
               
               
           
         
       
       to form the reaction product of formula IV 
       
         
           
           
               
               
           
         
         (c) adding one or more diamines of formula V to the reaction product of formula IV to form the repeat unit of formula I′ 
       
       
         
           
           
               
               
           
         
       
       and
 (d) adding one or more amine-based capping agents of formula VI to halt polymerization and modify end groups of formula I′ 
 
       
         
           
           
               
               
           
         
         wherein R 4  is hydrogen or methyl, haloalkyl, aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo; G is alkyl (CH2)n, alkyl-aryl (CH2-Ar-CH2), aryl, heteroaryl, heterocycle, or carbocycle; and R 5  is hydrogen (as part of alkyl chain or aryl group), aryl, heteroaryl, a primary amine, secondary amine, tertiary amine, amide, carbamate, or urea. 
       
     
     
         2 . The method of  claim 1 , wherein amine-based capping agents of formula VI include propylamine, n-butylamine, tert-butylamine, aniline, 2-(aminomethyl)pyridine, 4-aminopyridine, benzylamine, N-acetylethylenediamine, and tert-Butyl N-(2-aminoethyl)carbamate (i.e., Boc-ethylenediamine), mixtures, and combinations thereof. 
     
     
         3 . The method of  claim 2 , wherein the amine based capping agent is N-acetylethylenediamine, ethylenediamine, and tert-Butyl N-(2-aminoethyl)carbamate, mixtures, and combinations thereof. 
     
     
         4 . The method of  claim 1 , wherein the oxalate ester of formula II is selected from the group consisting of oxalate esters of phenol, methyl ethyl ketone oxime, acetone oxime, and trifluoroethanol. 
     
     
         5 . The method of  claim 1 , wherein the solvent is selected from the group consisting of tetrahydrofuran, methyl tert-butyl ether, toluene, ethyl acetate, dichloromethane, and chloroform. 
     
     
         6 . The method of  claim 1 , wherein the polydiorganosiloxane diamine of formula III has a number average molecular weight of about 1000 g/mol to about 20,000 g/mol. 
     
     
         7 . The method of  claim 4 , wherein the polydiorganosiloxane diamine of formula III has a number average molecular weight of about 10,000 g/mol to about 17,000 g/mol. 
     
     
         8 . The method of  claim 1 , wherein the molar ratio of oxalate ester of formula II to polydiorganosiloxane diamine of formula III is at least 1:0.56. 
     
     
         9 . The method of  claim 1 , wherein the oxalate ester of formula II is fully consumed upon reacting with the polydiorganosiloxane diamine of formula III. 
     
     
         10 . The method of  claim 1 , wherein the method is performed in the presence of a protic acid catalyst. 
     
     
         11 . The method of  claim 10 , wherein the catalyst comprises acetic acid, and where the catalyst is added during at least one of step (c) and step (d). 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 10 , wherein the copolymer of formula I′ includes at least than 95 weight percent polydiorganosiloxane segments p based on the weight of the copolymer. 
     
     
         14 . The method of  claim 1 , wherein the diamine of formula V is selected from the group consisting of 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 2-methyl-1,5-pentanediamine, 1,6-diaminohexane, and m-xylylenediamine. 
     
     
         15 . The method of  claim 1 , wherein the molar ratio of polydiorganosiloxane diamine of formula III to the sum of the diamine of formula V and the capping agent of formula IV is less than or equal to about 1:0.8. 
     
     
         16 . The method of  claim 1 , wherein the molar ratio of the polydiorganosiloxane diamine of formula III to the sum of the diamine of formula V and the capping agent of formula IV to the oxalate ester of formula II is about 0.55:0.45:1. 
     
     
         17 . (canceled) 
     
     
         18 . The method of  claim 1  wherein each R 1  is methyl. 
     
     
         19 . The method of  claim 1  wherein each Y is an alkylene having 1 to 10 carbon atoms, phenylene bonded to an alkylene having 1 to 10 carbon atoms, or phenylene bonded to a first alkylene having 1 to 10 carbon atoms and to a second alkylene having 1 to 10 carbon atoms. 
     
     
         20 . The method of  claim 1  wherein G is an alkylene, heteroalkylene, arylene, aralkylene, or a combination thereof. 
     
     
         21 . The method of  claim 1  wherein each R 3  is hydrogen. 
     
     
         22 . An article comprising the copolymer of formula I′ formed using the method of  claim 1 , wherein the article is a pressure sensitive adhesive, film, mixture, or low adhesion backsize. 
     
     
         23 . An adhesive composition, comprising the copolymer of formula I′ formed using the method of  claim 1 , a silicate tackifying resin, and optionally inorganic particle filler. 
     
     
         24 - 26 . (canceled) 
     
     
         27 . The adhesive composition of  claim 21  wherein the adhesive composition demonstrates a shear strength of greater than 10,000 minutes as measured according to CTH modified ASTM D3654-82. 
     
     
         28 . (canceled)